TRANSPORTE DE GAMETAS, FERTILIZAÇÃO E SEGMENTAÇÃO -/- • _____OBJETIVO -/- O entendimento do desenvolvimento embrionário nos estágios iniciais, desde a deposição dos espermatozoides na fêmea, passando pela fertilização deste no ovócito e na formação do zigoto, é de suma importância para diferenciar especialistas em reprodução e manejo reprodutivo no mercado de trabalho e, também, durante a vida acadêmica. Compreender os processos que levam à formação do zigoto na fêmea é essencial para avaliar a capacidade reprodutiva dos animais e, mediante técnicas, (...) avaliar o trato reprodutivo da fêmea e o desenvolvimento do embrião até a formação do feto e, por fim, em um novo animal sadio na propriedade. Com esse trabalho, o estudante de veterinária ou zootecnia, que deseja se aprofundar na fisiologia da reprodução animal, identificará os mecanismos que são envolvidos no transporte dos gametas, bem como os processos que estes últimos devem completar para alcançar a fertilização e para desencadear as divisões iniciais do embrião. -/- • _____INTRODUÇÃO -/- A fertilização ou fecundação é o processo pelo qual os gametas masculino (espermatozoide) e feminino (ovócito) se fundem para gerar um novo indivíduo. Seu êxito depende da culminação adequada dos diferentes processos que devem sofrer os gametas durante sua maduração e percurso; do transporte oportuno destes no trato reprodutivo da fêmea, assim como de uma série de adaptações dos órgãos genitais internos da mãe. A segmentação refere-se às primeiras divisões celulares do embrião. -/- • _____TRANSPORTE DO OVÓCITO -/- O ovócito que é liberado na ovulação, e que se encontra coberto pelas células do cumulus (figura 1), é capturado pela fímbria do infundíbulo ao aderir aos cílios. Esse processo é altamente eficaz, inclusive em espécies onde os ovários possuem várias formações globosas, por exemplo nas porcas, onde os ovidutos capturam entre 95 e 100% dos ovócitos que são ovulados. As contrações das camadas musculares do oviduto e o movimento intenso dos cílios da mucosa faz com que as secreções fluam em direção ao útero, transportando assim o complexo cumulus-ovócito. Esse transporte é relativamente rápido até alcançar a junção da ampola com o istmo (que é considerado o local de fertilização do espermatozoide e ovócito) a partir do qual se torna lento. Devido a fêmea estar em estro, o processo está sob controle endócrino, isto é, controle hormonal através do estradiol. Nas fêmeas domésticas, ao contrário das mulheres, o transporte ao longo do oviduto é extremamente eficiente, pois os embriões passam para o útero sem dificuldade, de modo que gestações ectópicas (tubárias ou em cavidade) são quase inexistentes. A égua, frequentemente, retém por muito tempo os ovócitos não fertilizados no oviduto, provavelmente devido a não secreção de substâncias (como a prostaglandina E) que poderiam favorecer sua passagem, como se propõe que aconteça com os embriões. A figura 2 apresenta um ovócito com suas respectivas estruturas. Figura 1: ovócitos de uma vaca madurados in vitro. Nota-se as células do cumulus que os recobre. -/- Figura 2: estruturas do ovócito de uma ovelha que se encontra na etapa de ovócito secundário, depois da ovulação. Elaborado pelo autor. • _____TRANSPORTE ESPERMÁTICO -/- Para que os espermatozoides sejam capazes de fertilizar o ovócito, deverão sofrer uma série de mudanças bioquímicas e morfológicas ao longo de sua passagem pelo aparelho reprodutor tanto masculino como feminino. Uma vez produzidos na parede do túbulo seminífero, os espermatozoides são liberados em direção ao lúmen tubular e transportados passivamente para uma estrutura ramificada conhecida como rede testicular (rete testis). Dessa rede são conduzidos em direção ao epidídimo passando através de 10 a 20 ductos eferentes localizados no polo superior do testículo. O epidídimo é dividido em três seções denominadas cabeça, corpo e cauda; é constituído por um só ducto longo e tortuoso que continua com o canal deferente. Ao final desemboca nas ampolas seminais, no ducto ejaculatório e na uretra. As funções do epidídimo são as de maduração, transporte e armazenamento dos espermatozoides. O transporte através do epidídimo é lento, aproximadamente de 10 dias em touros, e segue sendo passivo. Os espermatozoides tomados da cabeça do epidídimo são ainda imaturos e incapazes de fertilizar, enquanto os armazenados na cauda são completamente maduros. Durante o trânsito pelo epidídimo os espermatozoides adquirem motilidade e o potencial para fertilizar, o acrossomo é remodelado e a gota citoplasmática migra para o flagelo e é liberada. Quando um macho ejacula com muita frequência, é possível observar espermatozoides com gota citoplasmática no sêmen, já que não há tempo suficiente para que completem sua maduração. Os espermatozoides são expulsados fora do organismo durante a cópula, na masturbação ou em emissões espontâneas. Na ejaculação, os espermatozoides que se encontram suspensos nos fluidos do testículo e do epidídimo, misturam-se ao chegar na uretra com as secreções das glândulas acessórias para formar o sêmen. Essas secreções denominadas plasma seminal, proporcionam substâncias para manter o metabolismo energético das células espermáticas, e integram suas membranas elementos que impedem uma capacitação prematura. Durante a cópula, o sêmen é depositado na vagina ou no útero, variando entre as espécies (tabela 1). Na monta natural, geralmente, o serviço ocorre no momento propício, já que está definido pela fase do ciclo estral em que a fêmea é receptiva ao macho. No entanto, na inseminação artificial, é o macho que deverá determinar o momento ideal, e para isso é importante considerar a vida média dos gametas, ao qual é muito curta no caso dos ovócitos (tabela 1). -/- Tabela 1: local de depósito do sêmen, volume da ejaculação e vida média dos gametas. Espécie Local de deposição Volume (ml) Velocidade de ejaculação Vida média do ovócito Vida média do espermatozoide Bovinos Intravaginal 2 1 – 3 seg 8 h 30 – 48 h Caninos Intravaginal 2 – 30 (10 média) 6 – 45 min 48 – 72 h 9 – 11 d Equinos Intrauterina 50 – 200 20 – 60 seg 6 – 8 h 72 – 120 h Humanos Intravaginal 3 - - 5 – 6 d Ovinos Intravaginal 1 1 – 2 seg 16 – 24 h 30 – 48 h Suínos Intrauterina 200 – 400 5 – 20 min 8 – 10 h 24 – 48 h Onde d = dias; h = horas. A vida fértil do ovócito é muito curta, portanto, o momento do serviço é de grande importância para obter altos índices de fertilização. -/- Independentemente do local em que os espermatozoides sejam depositados no aparelho reprodutor feminino, serão expostos às secreções genitais e sofrem uma série de mudanças em seu trajeto até o local de fertilização antes de penetrar no ovócito. Nas espécies em que o sêmen é depositado na parte cranial da vagina, uma parte do mesmo penetra através da cérvix, enquanto outra parte é eliminada do aparelho genital da fêmea, em pouco tempo, através do fluxo retrógrado. O meio vaginal não é adequado e imobiliza os espermatozoides em pouco tempo, pelo qual deverão entrar no útero onde o ambiente é mais propício. O transporte espermático na fêmea é o resultado da alta contratilidade, do movimento ciliar e o fluido do aparelho genital durante o estro, ao qual está sob controle endócrino e do sistema nervoso. Esse transporte é favorecido pelas características especiais do muco estral, cujas moléculas formam uma espécie de canais que facilitam a passagem dos espermatozoides. Pelo contrário, durante a fase lútea seu transporte é dificultado. Além do meio vaginal, a cérvix também atua como barreira natural para limitar a passagem dos espermatozoides, diminuindo assim a possibilidade de polispermia. Funciona, também, como um filtro que seleciona os espermatozoides aptos dos que não o são, uma vez que somente os primeiros possuem uma motilidade vigorosa que lhes permite passar pelo muco altamente hidratado. Na vaca a cérvix é considerada como um reservatório espermático. Quando atravessam a cérvix, os espermatozoides seguem sua deslocação tanto por movimento próprio como pelas contrações uterinas e tubárias. Nas espécies em que o local de depósito do sêmen do macho na fêmea é intrauterino, como equinos, a principal barreira que os espermatozoides enfrentam é a união ou junção útero-tubárica. A união entre o útero e o oviduto (istmo do oviduto) serve como reservatório funcional dos espermatozoides nas espécies domésticas. Poucos minutos depois da cópula, é possível encontrar alguns espermatozoides no oviduto, que é conhecido como fase de transporte rápido. No entanto, esses espermato-zoides não são os que participam do processo de fertilização e podem apresentar certas anormalidades. Existe um segundo tipo de transporte denominado fase sustentada, a qual consiste na migração prolongada dos espermatozoides em direção as partes mais craniais do aparelho genital feminino, que conduzem à colonização do reservatório funcional e na liberação gradual dos espermatozoides dos reservatórios espermáticos, incluindo este último. O reservatório do istmo fornece aos espermatozoides um ambiente propício, protegendo-os contra a fagocitose, prolongando assim a sua viabilidade. Aqui os esper-matozoides permanecem aderidos a superfície das células ciliadas do epitélio até a finalização de sua capacitação, depois da qual são liberados quando alteram seu padrão de motilidade flagelada, fenômeno conhecido como hipermotilidade, e migram em ondas em direção ao local da fertilização. Dos milhões de espermatozoides ejaculados, somente alguns milhares alcançarão o istmo do oviduto e um número sumamente pequeno será encontrado nas imediações do ovócito no momento da fertilização. -/- • _____CAPACITAÇÃO ESPERMÁTICA E REAÇÃO ACROSSÔMICA -/- A capacitação é um processo gradual e essencial para a fertilização. Os espermato-zoides devem passar por um dado tempo de “incubação” no aparelho genital da fêmea e sofrer uma série de mudanças antes de serem capazes de fecundar o ovócito. A capacita-ção dos espermatozoides começa quando eles entram em contato com as secreções do aparelho genital da fêmea e termina no istmo do oviduto. Durante esse percurso a superfície da cabeça do espermatozoide se modifica já que algumas moléculas como o colesterol são removidas da membrana plasmática, aumentando sua fluidez e alterando suas propriedades bioquímicas. Entre outras coisas, essa reorganização dos lipídios facilita a entrada de cálcio extracelular pelos canais iônicos e ocasiona a desestabilização da membrana, tornando-a mais fusogênica. Também são eliminados outros fatores (conhecidos genericamente como fatores descapacitantes) que expõem receptores membranais indispensáveis para a realização da união entre o espermatozoide e o ovócito durante a fertilização. Os espermatozoides capacitados apresentam um padrão de hipermotilidade e uma maior atividade metabólica, características que devem obter para que sejam capazes de penetrar as camadas do ovócito. A capacitação é necessária para que ocorra a reação acrossômica. A reação acrossomal ou acrossômica (RA) é um fenômeno de exocitose que é desencadeada pela ligação entre as proteínas e receptores localizados na membrana do espermatozoide e a zona pelúcida do ovócito (figura 3). Envolve a fusão da membrana plasmática do espermatozoide com a membrana externa de seu acrossomo; formando, assim, pequenas vesículas, cujo conteúdo de enzimas hidrolíticas, como a hialuronidase e a acrosina, é liberado em direção ao seu exterior, facilitando a penetração da zona pelúcida. A adesão do espermatozoide à zona pelúcida é específica da espécie e depende de glicoproteínas presentes na membrana dos ovócitos maduros; a cabeça do espermatozoide se une com essas glicoproteínas mediante receptores específicos e atravessam em direção oblíqua a zona pelúcida até chegar ao espaço perivitelino. Nos mamíferos, particularmente em roedores e nos humanos, algumas dessas glicoproteínas são conhecidas como ZP1, ZP2 e ZP3. Pensa-se que a união da membrana espermática a esta última é o que desencadeia a reação acrossomal. Posteriormente, as vilosidades do ovócito entram em contato com o espermatozoide e a membrana presente na secreção equatorial da cabeça do espermatozoide, que tem proteínas fusogênicas específicas, une-se a membrana plasmática do ovócito, fusionando-se e permitindo a entrada do núcleo espermático ao citoplasma (figura 4). A capacitação dos espermatozoides é fundamental para o êxito da fertilização, uma vez que apenas os aptos estarão perfeitos e íntegros para que a união e percepção das glicoproteínas presentes nos mesmos possam ocorrer de forma ideal para a penetração deste no ovócito, fertilizá-lo e formar um zigoto. Figura 3: estrutura do espermatozoide. Nota: a membrana é acrossomal e não acrossonal. Elaborado pelo autor. -/- Figura 4: eventos que ocorrem durante a fertilização. A – depois de passar através das células do cumulus, o espermatozoide entra em contato com a zona pelúcida, onde receptores da membrana plasmática reconhecem as proteínas da zona pelúcida; B – é desencadeada, então, a reação acrossomal; C – para que o espermatozoide penetre na zona pelúcida; D – ao atravessar a zona pelúcida e entrar no espaço perivitelino, a cabeça do espermatozoide entra em contato com a membrana vitelina; ambas membranas se fusionam graças ao reconhecimento de proteínas fusogênicas que estão no segmento equatorial. E – ocorre, então, que o núcleo do espermatozoide penetra no citoplasma do ovócito; uma das consequências da fusão da membrana com a cabeça do espermatozoide é a reação cortical, em que os grânulos corticais do ovócito liberam seu conteúdo em direção ao espaço perivitelino, o que resulta na alteração da estrutura da zona pelúcida e da membrana vitelina para bloquear a polispermia. Elaborado pelo autor. • _____CONSEQUÊNCIAS DA PENETRAÇÃO -/- Bloqueio da polispermia -/- A fusão das membranas dos gametas durante a penetração permite a entrada da fosfolipase C zeta (PLCζ) – fator solúvel que provém do espermatozoide – que desencadeia liberação e oscilações de Ca2+ no retículo endoplasmático. Isso, por sua vez, provoca a migração e fusão dos grânulos corticais, com a consequente liberação de enzimas, que mudam tanto a estrutura da zona pelúcida (por exemplo a inativação de ZP3), como a da membrana vitelina. Desse modo, impede-se que outros espermatozoides as penetrem, evitando assim a polispermia (figura 5). -/- Figura 5: os grânulos corticais que encontram-se na periferia do citoplasma, debaixo da superfície da membrana do ovócito, migram e fusionam-se sobre a mesma, liberando seu conteúdo no espaço perivitelino imediatamente depois da penetração do espermatozoide. A – como conse-quência, tanto a membrana vitelina como a zona pelúcida são modificadas, impedindo a entrada de mais espermatozoides, o que evita a polispermia. B – o ovócito retoma, então, sua segunda divisão meiótica, que ocasiona a expulsão do segundo corpúsculo polar, e na formação dos pronúcleos feminino e masculino. C – continuando, os pronúcleos migram, suas membranas se dissolvem e os cromossomos de ambos se condensam e se unem. Completa-se, assim, a singamia e forma-se, então, o zigoto. Elaborado pelo autor baseado nos livros de embriologia e fisiologia da reprodução conforme vida bibliografia. -/- Ativação do ovócito e formação de pronúcleos -/- Na maioria das fêmeas domésticas, com exceção da cadela, o ovócito encontra-se suspenso na metáfase II da segunda meiose no momento da ovulação. A entrada da PLCζ do espermatozoide no citoplasma do ovócito, e a consequente liberação de Ca2+, faz com que o ovócito se ative, terminando a segunda divisão meiótica e expulse o segundo corpo polar. Posteriormente, o material nuclear do ovócito se reorganiza para formar o pronú-cleo feminino. Entretanto, a membrana nuclear do espermatozoide se dissolve, a cromatina descondensa-se, as protaminas são substituídas por histonas, e se forma uma nova membrana nuclear, dando lugar ao pronúcleo masculino. -/- Singamia -/- Uma vez que os pronúcleos feminino e masculino são formados, migram para o centro do ovócito, aproximam-se, suas membranas se dispersam e os cromossomos paternos e maternos se associam, com o qual recupera a condição diploide e dá origem ao zigoto (figura 5). -/- • _____DESENVOLVIMENTO EMBRIONÁRIO -/- Poucas horas após a fertilização ocorre a primeira divisão do zigoto em duas, depois em 4, 8, 16 e 32 células, denominadas blastômeros. Essas divisões mitóticas são conhecidas como divisões de segmentação ou clivagem (figura 6), uma vez que são realizadas sem aumento do citoplasma, de modo que com cada divisão os blastômeros se tornam menores. A partir das 16 células o embrião se chama mórula, e é visto como uma massa celular compacta. A compactação deve-se a informação de proteínas de ligação entre os blastômeros. O embrião acumula líquido em seu interior, formando uma cavidade denominada blastocele. Esse processo é conhecido como blastulação; o embrião, assim, passa a ser chamado de blastocisto. Nessa etapa é possível diferenciar duas populações de células embrionárias: a massa celular interna, embrioblasto ou botão embrionário (que dará origem ao embrião), e a massa celular externa, células superficiais ou trofoblasto, do qual se originam a maioria das membranas fetais. Ao continuar a multiplicação das células e a acumulação de líquido, o blastocisto aumenta de tamanho, convertendo-se em blastocisto expandido. A zona pelúcida torna-se mais fina e, finalmente, o embrião eclode; isto é, o embrião é liberado da zona pelúcida. -/- • _____FERTILIZAÇÕES ATÍPICAS -/- Polispermia -/- É a penetração de dois ou mais espermatozoides no óvulo. Esta condição é letal nos mamíferos, já que o número cromossômico desse zigoto é maior que 2n, o envelheci-mento do ovócito da porca, como consequência do serviço tardio, favorece a apresentação da polispermia, por isso, é comum ver números de nascimentos de média de 10 a 12 leitões por parição nessa espécie. Nas aves, no entanto, a penetração de mais de um espermatozoide é normal, embora apenas um pronúcleo masculino se formará, fundindo-se com o feminino. -/- Figura 6: etapas do processo de segmentação/clivagem. Fonte: aula de reprodução da professora Domenica Palomaris, UFT. -/- Ginogênese -/- É o desenvolvimento de um embrião a partir de um óvulo normal fecundado por um espermatozoide, mas sem a fusão dos cromossomos masculinos com os da fêmea. A função do espermatozoide, nesse caso, é a de ativação do ovócito para que este inicie seu desenvolvimento, mas não há fusão com o núcleo do espermatozoide. Ocorre em plantas, em nematódeos e em algumas espécies de peixes, por exemplo a Poecilia formosa, espécie em que os ovócitos das fêmeas são ativados por machos de outra espécie relacio-nada. -/- Partenogênese -/- Consiste no desenvolvimento do embrião sem a participação do espermatozoide. Ocorre em alguns insetos, o zangão, por exemplo, é partenogenético. Também pode apresentar-se em perus, cujos embriões são machos e, geralmente, morrem antes da eclosão. -/- • _____GÊMEOS -/- Existem dois tipos de gêmeos: idênticos ou monozigóticos e os não idênticos ou dizigóticos. -/- Idênticos ou monozigóticos -/- Originam-se do mesmo zigoto, sendo assim, possuem o mesmo genótipo e um fenótipo similar e, portanto, são do mesmo sexo. Em laboratório é possível gerá-los ao seccionar uma mórula em duas ou mais partes, por meio de um micromanipulador. Uma vez que possuem o mesmo genótipo, os produtos resultantes são clones. -/- Não idênticos ou dizigóticos -/- Provêm da fertilização de dois óvulos distintos por espermatozoides diferentes. Possuem, portanto, genótipos e fenótipos diferentes, e podem ser de sexo diferente. -/- REFERÊNCIAS BIBLIOGRÁFICAS -/- ALBERTS, Bruce et al. Biologia molecular da célula. Artmed Editora, 2010. AUSTIN, Colin Russell; SHORT, Roger Valentine. Reproduction in Mammals, Book I: Germ Cells and Fertilization. 1982. BEARDEN, Henry Joe et al. Reproducción animal aplicada. México: Manual Moderno, 1982. BOSCH, P.; WRIGHT JR, R. W. The oviductal sperm reservoir in domestic mammals. Archivos de medicina veterinaria, v. 37, n. 2, p. 95-105, 2005. CAPALLEJAS, Roberto Brito; RODRÍGUEZ, Lourdes Tagle. Fisiología de la reproducción animal: con elementos de biotecnología. Editorial Félix Varela, 2010. CROXATTO, Horacio B. Physiology of gamete and embryo transport through the fallopian tube. Reproductive biomedicine online, v. 4, n. 2, p. 160-169, 2002. CUPPS, Perry T. (Ed.). Reproduction in domestic animals. Elsevier, 1991. DIEDRICH, Smidt et al. Endocrinología y Fisiología de la Reproducción de los Animales Zootécnicos. 1972. DUKES, Henry Hugh; SWENSON, Melvin J.; REECE, William O. Dukes fisiologia dos animais domésticos. Editora Guanabara Koogan, 1996. FERREIRA, A. de M. Reprodução da fêmea bovina: fisiologia aplicada e problemas mais comuns (causas e tratamentos). Juiz de Fora: Minas Gerais–Brasil, p. 422, 2010. HAFEZ, Elsayed Saad Eldin; HAFEZ, Bahaa. Reprodução animal. São Paulo: Manole, 2004. HUNTER, Ronald Henry Fraser. The Fallopian tubes in domestic mammals: how vital is their physiological activity?. Reproduction Nutrition Development, v. 45, n. 3, p. 281-290, 2005. HUNTER, R. H. F.; RODRIGUEZ‐MARTINEZ, H. Capacitation of mammalian spermatozoa in vivo, with a specific focus on events in the Fallopian tubes. Molecular Reproduction and Development: Incorporating Gamete Research, v. 67, n. 2, p. 243-250, 2004. GALINA, Carlos; VALENCIA, Javier. Reproducción de los animales domésticos. 2006. HOPPER, Richard M. (Ed.). Bovine reproduction. John Wiley & Sons, 2014. HYTTEL, Poul; SINOWATZ, Fred; VEJLSTED, Morten. Embriologia veterinária. Elsevier Brasil, 2012. KÖLLE, Sabine; REESE, Sven; KUMMER, Wolfgang. New aspects of gamete transport, fertilization, and embryonic development in the oviduct gained by means of live cell imaging. Theriogenology, v. 73, n. 6, p. 786-795, 2010. MCKINNON, Angus O. et al. (Ed.). Equine reproduction. John Wiley & Sons, 2011. OLIVERA, Martha et al. El espermatozoide, desde la eyaculación hasta la fertilización. Revista Colombiana de Ciencias Pecuarias, v. 19, n. 4, p. 426-436, 2006. PLANT, Tony M.; ZELEZNIK, Anthony J. (Ed.). Knobil and Neill's physiology of reproduction. New York: Academic Press, 2014. RODRIGUEZ-MARTINEZ, Heriberto. Role of the oviduct in sperm capacitation. Theriogenology, v. 68, p. S138-S146, 2007. SAAVEDRA LEOS, María Dolores. Estudio de la composición de los gránulos corticales y del oolema de ovocitos porcinos y bovinos madurados y fecundados in vitro. Proyecto de investigación:, 2010. SENGER, Phillip L. et al. Pathways to pregnancy and parturition. Current Conceptions, Inc, 2004. SUAREZ, Susan S. The oviductal sperm reservoir in mammals: mechanisms of formation. Biology of Reproduction, v. 58, n. 5, p. 1105-1107, 1998. VALENCIA MÉNDEZ, Javier de J. Fisiología de la reproducción porcina. 1986. -/- FIXAÇÃO DO ASSUNTO -/- 1. Defina e diferencie fertilização e segmentação. -/- 2. Disserte sobre o transporte do ovócito. Por que no istmo o transporte do ovócito se torna lento? -/- 3. Fale sobre a eficiência do transporte do gameta no trato genital da fêmea e sobre a retenção de ovócitos pela égua. -/- 4. Defina as células do cumulus e explique seu papel sobre o ovócito. -/- 5. Quais as estruturas que compõem o ovócito? Qual a função de cada uma? -/- 6. Todos os ovócitos das fêmeas domésticas são iguais? Justifique. -/- 7. Disserte sobre o papel dos hormônios e das secreções sobre o transporte do ovócito no trato genital da fêmea. -/- 8. Disserte sobre o transporte do espermatozoide. Por que há transporte rápido e lento dos espermatozoides? -/- 9. Fale sobre o local de deposição do sêmen nas espécies domésticas e como esse influen-cia na eficiência da reprodução. -/- 10. Por que a vida média do espermatozoide canino é maior que as outras espécies? -/- 11. Quais as mudanças que os espermatozoides precisam sofrer para conseguir êxito na fertilização e por quê? -/- 12. Defina fase de transporte rápido, fase sustentada e hipermotilidade. Qual a importân-cia de cada um? -/- 13. Como ocorre a reação acrossômica? -/- 14. O que é polispermia e como ocorre seu bloqueio? 15. Como ocorre a ativação do ovócito e como se formam os pronúcleos? -/- 16. O que é e qual a importância da singamia? -/- 17. Disserte sobre as divisões de segmentação e qual a importância destas para o êxito da reprodução. -/- 18. Defina e diferencia mórula e blastocisto. -/- 19. Defina e diferencie ginogênese e partenogênese. -/- 20. Qual o papel endócrino e quais hormônios e enzimas atuam sobre o transporte de gametas, sobre a fertilização e sobre a segmentação? (shrink)

The developing body of empirical work on the "Gettier effect" indicates that, in general, the presence of a Gettier-type structure in a case makes participants less likely to attribute knowledge in that case. But is that a sufficient reason to diverge from a JTB theory of knowledge? I argue that considerations of good model selection, and worries about noise and overfitting, should lead us to consider that a live, open question. The Gettier effect is perhaps so transient, and so sensitive (...) to other, epistemologically-inappropriate factors, that it raises the question of whether it ought to be counted as something to include in our theories -- or as a piece of noise to be excluded from them. (shrink)

En la obra de Hegel la filosofía de lo bello es eminentemente filosofía del espíritu. Uno de los temas insoslayables acerca de la belleza es su presencia en la naturaleza y en el arte. En las Lecciones de Estética la belleza del arte se pondera como la más excelente. En este punto la postura hegeliana diverge llamativamente de la de Schelling; quien trató explícitamente de la relación de las artes plásticas con la naturaleza, como consta en el texto que lleva (...) este tema por título (generalmente llamado “discurso de la academia”). Su propuesta es clara: la superioridad de la naturaleza frente a las artes plásticas. Lo más interesante de esta disputa no es el desacuerdo en sí mismo, sino las argumentaciones que uno y otro autor alegan a favor de sus tesis respectivas. (cuánto se parece y cuánto divergen) A través de ellas se pueden ver los diversos matices en torno a los conceptos de belleza y de espíritu. A esta cuestión es a lo que se dedicará esta comunicación: a analizar brevemente algunos argumentos de ambos autores acerca de la belleza en la naturaleza y en el arte. A lo largo de este artículo se lleva a cabo una comparación de textos, de algunas discrepancias concretas: en todas ellas lo llamativo es cómo son a la vez tan cercanos y tan contrarios. Tanto para Schelling como para Hegel, la belleza es del espíritu: lo más bello es lo que está penetrado de espíritu y es vivificado por él. Pero más allá de estos principios comunes hay mil matices que acaban desembocando en dos posturas contrapuestas. (shrink)

You may not know me well enough to evaluate me in terms of my moral character, but I take it you believe I can be evaluated: it sounds strange to say that I am indeterminate, neither good nor bad nor intermediate. Yet I argue that the claim that most people are indeterminate is the conclusion of a sound argument—the indeterminacy paradox—with two premises: (1) most people are fragmented (they would behave deplorably in many and admirably in many other situations); (2) (...) fragmentation entails indeterminacy. I support (1) by examining psychological experiments in which most participants behave deplorably (e.g., by maltreating “prisoners” in a simulated prison) or admirably (e.g., by intervening in a simulated theft). I support (2) by arguing that, according to certain plausible conceptions, character evaluations presuppose behavioral consistency (lack of fragmentation). Possible reactions to the paradox include: (a) denying that the experiments are relevant to character; (b) upholding conceptions according to which character evaluations do not presuppose consistency; (c) granting that most people are indeterminate and explaining why it appears otherwise. I defend (c) against (a) and (b). (shrink)

This paper examines the debate about the referential meaning of Kant’s concept of substance. In the Critique of Pure Reason and other works such as the Metaphysical Foundations of Natural Science, the category or concept of substance appears quite uncontroversially to have both a logical meaning (by which it means roughly ‘a thing that is the ultimate subject of predication’) and an objective meaning (by which it means roughly ‘a thing that is permanent’, or, equivalently, ‘a thing existing at all (...) times’). However, it is highly contested what kind of object, or objects, are supposed to meet, in experience, the criteria imposed by the conjunction of these two distinct meanings. I discuss two examples of the main interpretations to be found in the literature: Peter Strawson (2000), who contends that the reference of substance is only matter, and Claudia Jáuregui (2021), who also includes ordinary particular objects as substances. I scrutinize their fit with some of the textual evidence, primarily from the First Analogy of Experience, and finally reject Jáuregui’s interpretation as implying a kind of mereological essentialism about particular objects. Keywords: substance, meaning, matter, ordinary objects, First Analogy of Experience. (shrink)

Not focusing on the history of classical logic, this book provides discussions and quotes central passages on its origins and development, namely from a philosophical perspective. Not being a book in mathematical logic, it takes formal logic from an essentially mathematical perspective. Biased towards a computational approach, with SAT and VAL as its backbone, this is an introduction to logic that covers essential aspects of the three branches of logic, to wit, philosophical, mathematical, and computational.

Building on my previous exploration of the role of dance in the contemporary French political philosopher Jacques Rancière’s Aisthesis: Scenes from the Aesthetic Regime of Art, first published in French in 2011, the present essay turns to another book originally published in the same year, The Intervals of Cinema. Having previously established that the core of Rancière’s philosophical method is an analysis of philosophical homonyms into figurative dancing conceptual partners, I begin by applying that method to the first chapter of (...) Intervals, “Cinematic Vertigo: Hitchcock to Vertov and Back.” There I identify two series of such dancing partners, as follows: Hitchcock’s image-controlling, capitalist vertiginous fall, and Vertov’s movement-equalizing, communist balanced dance. I then critique the implicit marginalizing of women and female bodies in the films and chapter, including Hitchcock’s protagonist’s best friend and ex-fiancé, and Vertov’s cosmetologists and switchboard operators. Finally, I offer a corrective from the proto-feminist life of my grandmother, a onetime cosmetologist, switchboard operator, and Glamour Shots amateur model, my grandmother, Louise Nunnelley, or “Mamaw.” Such are the unacknowledged material basis of Rancière’s radical democratic philosophy, the specifically-embodied and positioned female dancers who continue to get lost in his figurative dance. (shrink)

In Flourish, the positive psychologist Martin Seligman (2011) identifies five commonly recognized factors that are characteristic of human flourishing or wellbeing: (1) “positive emotion,” (2) “relationships,” (3) “engagement,” (4) “achievement,” and (5) “meaning” (p. 24). Although there is no settled set of necessary and sufficient conditions neatly circumscribing the bounds of human flourishing (Seligman, 2011), we would mostly likely consider a person that possessed high levels of these five factors as paradigmatic or prototypical of human flourishing. Accordingly, if we wanted (...) to go about the practical task of actually increasing our level of wellbeing, we ought to do so by focusing on practically increasing the levels of the five factors that are characteristic of wellbeing. If, for instance, an activity such as musical engagement can be shown to positively influence each or all of these five factors, this would be compelling evidence that an activity such as musical engagement can positively contribute to one’s living a flourishing life. I’m of the belief that psychological research can and should be used, not only to identify and diagnose maladaptive psychological states, but identify and promote adaptive psychological states as well. In this article I advance the hypothesis and provide supporting evidence for the claim that musical engagement can positively contribute to one’s living a flourishing life. Since there has not yet been a substantive and up-to-date investigation of the possible role of music in contributing to one’s living a flourishing life, the purpose of this article is to conduct this investigation, thereby bridging the gap and stimulating discussion between the psychology of music and the psychology of wellbeing. (shrink)

Are living organisms--as Descartes argued--just machines? Or is the nature of life such that it can never be fully explained by mechanistic models? In this thought-provoking and controversial book, eminent geophysicist Walter M. Elsasser argues that the behavior of living organisms cannot be reduced to physico-chemical causality. Suggesting that molecular biology today is at the same point as Newtonian physics on the eve of the quantum revolution, Elsasser lays the foundation for a theoretical biology that points the way toward a (...) natural philosophy of organic life. Explicitly repudiating "vitalism" (the notion that the laws of nature need to be modified when applied to living organisms), Elsasser argues instead that the structural complexity of even a single living cell is "transcomputational"--that is, beyond the power of any imaginable system to compute. Beginning from this insight, Elsasser leads the reader through a step-by-step process that ultimately arrives at the conclusion that living and non-living matter are separated by "a no-man's land of irrationality." Trained in Germany as a physicist, Elsasser first pondered the implications of quantum mechanics for biology as early as 1951. The more closely he studied the inherent complexity of life, the more skeptical he became of the reductionist view of organisms as tiny machines. "An organism," he concluded, "is a source of causal chains which cannot be traced beyond a terminal point because they are lost in the unfathomable complexity of the organism." Like the physicist who works within the bounds of an unfathomable universe, Elsasser argues, the biologist must seek answers within a system that is no less unfathomable. (shrink)

PHILOSOPHY OF SCIENCE, vol. 52, number 1, pp.44-63. R.M. Nugayev, Kazan State |University, USSR. -/- THE HISTORY OF QUANTUM THEORY AS A DECISIVE ARGUMENT FAVORING EINSTEIN OVER LJRENTZ. -/- Abstract. Einstein’s papers on relativity, quantum theory and statistical mechanics were all part of a single research programme ; the aim was to unify mechanics and electrodynamics. It was this broader program – which eventually split into relativistic physics and quantummmechanics – that superseded Lorentz’s theory. The argument of this paper is (...) partly historical and partly methodological. A notion of “crossbred objects” – theoretical objects with contradictory properties which are part of the domain of application of two different research programs – is developed that explains the dynamics of revolutionary theory change. (shrink)

This book is the culmination of the COST Action CA15212 Citizen Science to Promote Creativity, Scientific Literacy, and Innovation throughout Europe. It represents the final stage of a shared journey taken over the last 4 years. During this relatively short period, our citizen science practices and perspectives have rapidly evolved. In this chapter we discuss what we have learnt about the recent past of citizen science and what we expect and hope for the future.

In Who's Afraid of Idealism? the philosophical concept of idealism, the extent to which reality is mind-made, is examined in new light. Author Luis M. Augusto explores epistemological idealism, at the source of all other kinds of idealism, from the viewpoints of Immanuel Kant and Friedrich Nietzsche, two philosophers who spent a large part of their lives denigrating the very concept. Working from Kant and Nietzsche's viewpoints that idealism was a scandal to philosophy and the cause of nihilism, Augusto evaluates (...) these philosophers and their role in shaping epistemological idealism. Using textual evidence from their writings and their reactions to western philosophers such as Plato, Descartes, and Hegel, Who's Afraid of Idealism? argues that in fact Kant and Nietzsche were really idealists at heart. In accessible prose, this text puts forward a theory that goes against current scholarly opinion, and even Kant and Nietzsche's opinions of themselves. (shrink)

In Cahn's brief article, he contests Philippa Foot's contention that “Great happiness, unlike euphoria or even great pleasure, must come from something related to what is deep in human nature, and fundamental in human life, such as affection for children and friends, the desire to work, and love of freedom and truth,” contesting her claim with the counterexample of a person, "Fred," not unlike people Cahn has known, who is perfectly contented with their role, not unlike the figure painted by (...) Glaucon in Book 2 of Plato's Republic, a "completely unjust person [who,] while doing the greatest injustice, [...] has nonetheless provided himself with the greatest reputation for justice.". (shrink)

In this paper I consider the possibility of a kind of a priori cognition that serves the purposes of metaphysics, given that metaphysics involves the search for modal knowledge. Necessary or, better, modal knowledge is a priori; so metaphysical knowledge is likewise a priori. Here I argue that intuition is the route to modal knowledge in metaphysics, and I insist that conceivability or knowledge of conceptual truths does not lead towards the modal realm of metaphysics.

In lieu of an abstract, here is a brief excerpt of the content:Epistemic Leaks and Epistemic Meltdowns: A Response to William Morris on Scepticism with Regard to Reason Mikael M. Karlsson I. In an excellent paper which appeared in the April, 1989 issue of this journal,2 William Morris attemptsto demonstrate thatthe arguments which make up Hume's notorious chapter, "Of scepticism with regard to reason, are, in the first place, coherent—both internally and with the overall strategy of the Treatise—and, in the (...) second place, successful. Morris' paper is an exercise in the noble art of what I style constructive exegesis, an enterprise to which many readers of Hume Studies, and myself as much as any, are committed. It is a guiding principle ofthis art that we donotunderstandaphilosophical textuntil we can interpret it in such a way as to render it both coherent and correct. From this point ofview, coherence and correctness are not as independent of one another as they may seem to be to others who are differently committed. Some texts, such as Hume's chapter, "Ofscepticism with regard to reason," are notoriously resistant to constructive exegesis, despite the formidable bag of tricks which scholars and interpreters have developed; so resistant, that in gloomier moments we may be brought to wonder about our interpretative enterprise itself. Constructive exegesis is indeed a strange, and peculiarly optimistic, enterprise. Someday, I imagine, in a leisurely moment, I will think more reflectively about the principles ofour art. But not now.6 As a fellow practitioner of constructive exegesis, I am in full sympathy with what Morris tries to do in his paper; and I think that he does contribute substantially to our understanding of what Hume is up to in the chapter, "Ofscepticism with regard to reason." The third section of Morris' paper is, in my judgement, particularly successful in showing how Hume's chapter fits into the larger framework of the Treatise: Hume is, we see, attacking both what Morris labels "intellectualist rationalism" and its counterpart, which we may call 'unmitigated scepticism', although the chapter's two main arguments go primarily to the former. I also think that Morris gives very helpful, Volume XVI Number 2 121 MIKAEL M. KARLSSON and to my mind accurate, accounts of these two arguments, which I dub, respectively, the epistemic leak argument, and the epistemic meltdown argument. However, I have personally never found either of these arguments remotely convincing; and I still do not, despite Morris' clarification and defense. In what follows, I shall indicate some ofthe reasons for my dissatisfaction.?. Theepistemicleakargumentpurportsto"prove"(in Hume's sense)that reason or demonstration cannot support knowledge. Morris rightlyreminds us that whatHume meansby knowledge is perfect assurance or conviction: Knowledge is, in short, subjective certainty. This has caused confusion, for this is not what we usually mean nowadays by knowledge; nor was it what people, philosophers included, generally meant prior to Descartes. In Hume itis the product ofthe attempttoresolve all epistemic statesintomental eventsorwhat he calls "perceptions." In any case, we must—as Morris rightly explains—be clear that the epistemic leak argument is aimed at showing that demonstration cannot supportperfect conviction. Inoutline, the argumentissimple: Itworks, asMorrismakes clear, by shifting attention away from the subject-matter or "objects" of demonstration, that is, relations of ideas, to the exercise of demonstrative reason by human agents. The necessity of relations of ideas may suggest to us that we can be certain about them. Against this, one may point out that people do err in the conclusions arrived at by demonstration; this presumably shows that our (rational) understandingis fallible. And once we recognize this, our confidence in any conclusion produced by exercising this facultyislessened—thus do we move from knowledge, or subjective certainty, toprobability: belief, or imperfect conviction. Arguments ofthis general type (we can call them, using Descartes' famous figure, Totten-apple arguments ) were around long before Hume, although they were more commonly directed against the senses than against reason. We find them in antiquity—in Plato and Sextus Empiricus, for instance —and in Descartes, in parallel passages in the Discourse on Method, the First Meditation and the Principles of Philosophy, wherein one can discern a version directed precisely against reason and demonstration.12 To find out what, if anything, Hume has... (shrink)

This paper explores how open-mindedness and its exercise can be social in nature. In particular, it argues that an individual can be regarded as open-minded even though she does not conduct all of the intellectual tasks as required by open-mindedness _by herself;_ that is, she delegates some of these tasks to her epistemic peers. Thinking about open-mindedness in such social terms not only opens up the possibility that there are different and surprising ways for an individual to be open-minded, but (...) can also help offset some recent criticisms raised against open-mindedness and its status as an intellectual virtue. (shrink)

INTERNATIONAL STUDIES IN THE PHILOSOPHY OF SCIENCE Vol. 10, number 2, 1996, pp. 127-140. R.M. Nugayev. Why did the new physics force out the old ? Abstract. The aim of my paper is to demonstrate that special relativity and the early quantum theory were created within the same programme of statistical mechanics, thermodynamics and Maxwellian electrodynamics reconciliation. I’ll try to explain why classical mechanics and classical electrodynamics were “refuted” almost simultaneously or, in other words, why the quantum revolution and the (...) relativistic one both took place at the beginning of the 20th century. I’ll argue that the quantum and relativistic revolutions were simultaneous since they had a common origin – the clash beyween the mature theories of the second half of the 19th century that constituted the “body” of classical physics. The revolution’s most dramatic point was Einstein’s 1905 photon paper that laid the foundations of both special relativity and the old quantum theory. Hence the dialectic of the old theories is crucial for theory change. Later, classical physics was forced out by the joint development of quantum and relativistic subprogrammes. The title of my paper can be reformulated in Bruno Latour’s terms: The Einstein Revolution or Drawing Models Together. -/- . (shrink)

Inspired by Charles Taylor’s locating of Herder and Rousseau’s “expressivism” in Marx’s understanding of the human as artist, I begin this essay by examining expressivism in Taylor, followed by its counterpart in M. H. Abrams’s work, namely the wind as metaphor in British Romantic poetry. I then further explore this expressivism/wind connection in Percy Bysshe Shelley’s “Ode to the West Wind” and Marx’s The German Ideology. Ultimately I conclude that these expressive winds lead to poetic gesture per se, and thereby, (...) to a kind of poetry at the heart of Marx’s philosophy. (shrink)

It is worth exploring the longstanding preoccupation with the future that can be found throughout H. Odera Oruka's writings, especially the writings to be found in a retrospective collection of his essays on which he was working at the time of his death, Practical Philosophy: In Search of An Ethical Minimum. This practice of tracing the future results of actions of which people are presently engaged, in order to determine whether a change of course is needed, is not something that (...) Odera Oruka had to go to a university to learn. When Odera Oruka takes up Futures Studies, it is not to embrace a foreign way of thinking, but to find the international complement to the local approach well known and practiced by Africans. (shrink)

In this editorial, I explain how Paul Feyerabend's Principle of Proliferation is adopted and adapted as a publication model for the Journal of Knowledge Structures and Systems (JKSS). Critical views on the limitations of both non-dynamic publishing models and government- and industry-based models of research are expressed.

The objectively best language is intended to refer to some metaphysically privileged language that ‘carves reality at its joints’ perfectly. That is, it is the kind of language that various ‘metaphysical deflationists’ have argued is impossible. One common line of argument amongst deflationists is that we have no means to compare languages that all express true facts about the world in such a way to decide which is ‘better’. For example, the language is physics is not objectively better than the (...) language of economics, as each language has the semantic purpose of expressing some domain of truths about the world inexpressible in the other language, and therefore neither could be ‘objectively best’. In this paper, I argue that metaphysical deflationists have failed to recognise a distinction between fine- and coarse-grained semantic purposes of languages, and that a recognition of that distinction provides us grounds to compare languages to see which is objectively best. I argue that once we recognise the distinction between fine- and coarse-grained semantic purposes, then we can see that it is relative to the coarse-grained purpose that we must compare putative objectively best ontological languages. (shrink)

This paper analyses how security affects well-being. Security is understood as someone’s sureness of enjoying some good in the future; well-being is treated as a matter of human flourishing. Security can contribute to our well-being in various ways: if we are in fact bound to enjoy a good, in principle this is positive for our flourishing in the future; if we also believe that we will enjoy this good, we can be more efficient in pursuing our well-being; if we also (...) feel secure, this supports our enjoyment of our physical and mental capacities. For some of these benefits to obtain fully, however, it is important that our beliefs and feelings align with the facts. Furthermore, mirroring security’s upsides, there are also ways in which security can hamper our flourishing: it can obstruct the change, surprise, and pleasurable fear that are sometimes required for a good life too. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:This Universalism Which Is Not OneLinda M. G. Zerilli (bio)Ernesto Laclau. Emancipation(s). London: Verso, 1996.Judging from the recent spate of publications devoted to the question of the universal, it appears that, in the view of some critics, we are witnessing a reevaluation of its dismantling in twentieth-century thought. One of the many oddities about this “return of the universal” 1 is the idea that contemporary engagements with it are (...) more or less of a piece, and that they reflect a growing consensus that poststructuralist political theories are incapable of generating a viable alternative to the collective fragmentation that characterizes late modernity. 2 The putative return to the universal marks, on this view, both a homecoming to Enlightenment ideals—purified of their more poisonous elements, of course—and a reconciliation of sorts between those who refuted these ideals and those who sought to realize them. Now that “we” all know and agree that poststructuralism is critically valuable but politically bankrupt; now that we all know and agree that the “old universal” was indeed a “pseudo-universal,” so the homecoming narrative goes; we can get on with the project of constructing a “new universal.” 3 This authentic universal would really be inclusive of all people, regardless of race, class, gender, sexuality, ethnicity, nationality, and whatever else attaches to the “embarrassing etcetera” that, as Judith [End Page 3] Butler reminds us, inevitably accompanies such gestures of acknowledging human diversity.Before signing on to this felicitous agreement about “the necessity of universalism,” we may wish to know whether we have anything like a minimal agreement in language, that is, whether we who speak of this universal are even speaking about the same thing. Apart from the not insignificant problem of translating from a philosophical to a political idiom, the whole question of this agreement is virtually occluded by the rush to rescue politics from the virulent particularisms that admit no common ground or sense of collective belonging. Presented in terms of the familiar binary couple, the choice between universalism and particularism seems settled by merely pointing to global and domestic political realities. Universalism is the only alternative to social fragmentation, wild child of the collapse of communism, the rise of deadly nationalisms, and the multiculturalist romance with particularism. To invoke the name of the universal in any affirmative sense is already to sign on to the political diagnosis and its solution.One of the many virtues of Ernesto Laclau’s Emancipation(s) is that it offers both an alternative to the binarisms spawned by the “return” to the universal (for example, false universalism/true universalism) and a trenchant critique of the original binary couple itself (universalism/ particularism). Demonstrating the imbrication of the universal and the particular, Laclau shows why it is a matter not of choosing one over the other but of articulating, in a scrupulously political sense, the relation between the two. He thus explicitly rejects the notion that this relation is one of mutual exclusion, and shows that the tendency to see it as just that has led to the impasse of the contemporary debate, an impasse that is glossed over in some highly visible academic cases by proclaiming the necessary return to the universal. Although the language of universalism as spoken by Laclau searches for some common ground between particularists and universalists, it is more by way of articulating their mutual contamination, that is, how each is rendered impure by the irreducible presence of the other.The Problem of UniversalsLaclau situates his collection of essays in the context of the increasingly polarized debate over multiculturalism, a debate in which the classical universalism of the philosophical tradition has come under serious question. Reading his essays, one comes to see the deep dependence of the entire contemporary discussion on this tradition, even when its metaphysical assumptions are explicitly rejected (as, say, in the work of Seyla Benhabib) or insufficiently comprehended (as in most of the popularized political discourse). Laclau’s book can help us to see that the political question of universalism cannot be posed properly as long as it remains tethered to the classical philosophical “problem of universals.” At stake in sorting out the affinities and... (shrink)

Kant's claim that time is a subjective form of intuition was first proposed in his Inaugural Dissertation. This view was immediately criticised by Schultz, Lambert and Mendelssohn. Their criticisms are based on the claim that representations change which implies that change is real. From the reality of change they then argue to the reality of time, which undermines its supposed status as a subjective form of intuition that only applies to appearances. Kant took these criticisms very seriously and attempted to (...) reply to them in § 7 of the Transcendental Aesthetic. This paper provides a critical assessment of the objections raised by Schultz, Lambert and Mendelssohn as well as of Kant's diagnosis and response. In particular, it shows how Kant can consistently hold that knowledge of our mental states is restricted to knowledge of appearances. (shrink)

Vera Zasulich’s shooting of Trepov, a governor of St Petersburg who had ordered the flogging of a political prisoner, in January 1878, catapulted her to international fame as a revolutionary heroine, a reputation that she put to good use by becoming one of the five ‘founding parents’ of Russian Marxism that created the ‘Group for the Emancipation of Labour’ in 1883. But her act of self-sacrifice also triggered, to her dismay, the institutionalisation of individual terrorist tactics in the Russian Populist (...) movement with the creation of the ‘People’s Will’ (Narodnaya Volya) Party in 1879. The organisation went into decline after the killing of Tsar Alexander II in 1881, and Populism itself was increasingly superseded by Marxism as the hegemonic force on the left with the rise of the Russian Social Democratic Labour Party (RSDLP). But individual terrorist tactics reappeared with the creation of the Socialist Revolutionary Party in 1902, prompting Zasulich to write an article for Die neue Zeit, the theoretical organ of German Social Democracy, in which she both condemned the Neo-Populist tendency as deleterious to the rising labour movement and supported the organisational plans for the RSDLP sponsored by the Iskra group, developed at length by Lenin in his book What Is to Be Done?, published in March 1902. This article provides the background to Vera Zasulich’s article ‘The Terrorist Tendency in Russia’ (December 1902), setting it against the history of the Russian revolutionary movement from 1878 to 1902. (shrink)

Genesis of the early quantum theory represented by Planck’s 1897-1906 papers is considered. It is shown that the first quantum theoretical schemes were constructed as crossbreed ones composed from ideal models and laws of Maxwellian electrodynamics, Newtonian mechanics, statistical mechanics and thermodynamics. Ludwig Boltzmann’s ideas and technique appeared to be crucial. Deriving black-body radiation law Max Planck had to take the experimental evidence into account. It forced him not to deduce from phenomena but to use more theory instead. The experiments (...) forced Planck to apply the statistical technique to radiation in increasing portions. Planck’s theories in no way were generalizations of existing experimental results. They represented the stages of an ambitious programme of Maxwellian electrodynamics and statistical mechanics reconciliation. (shrink)

This paper examines how the concepts of utility, impartiality, and universality worked together to form the foundation of Adam Smith's jurisprudence. It argues that the theory of utility consistent with contemporary rational choice theory is insufficient to account for Smith's use of utility. Smith's jurisprudence relies on the impartial spectator's sympathetic judgment over whether third parties are injured, and not individuals' expected utility associated with individuals' expected gains from rendering judgments over innocence or guilt.

This paper sketches a brief account of multiculturalism in order to distinguish it from other positions that have been under attack recently. Following this, we address two prevalent and diametrically opposed criticisms of multiculturalism, namely, that multiculturalism is relativistic, on the one hand, and that it is absolutist, on the other. Both of these criticisms, we argue, simply mask liberal democratic theory's myth- begotten attempt to resolve the tension between the one and the many. Multiculturalism challenges the myths of meritocracy (...) and abstract individualism which underlie liberalism; properly understood, it evades the criticisms often hurled at it. (shrink)

Abstract. Following the tracks of Ryle and based upon the theory of complex systems, we shall develop a characterization of action-based consciousness as an embodied, embedded, selforganized process in which action and dispositions occupy a special place. From this perspective, consciousness is not a unique prerogative of humans, but it is spread all around, throughout the evolution of life. We argue that artificial systems such as robots currently lack the genuine embodied embeddedness that allows the type of self-organization that is (...) relevant to consciousness. -/- Sommario. Seguendo la linea tracciata da Ryle e basata sulla teorie dei sistemi complessi, svilupperemo una caratterizzazione della coscienza basata sull’azione come un processo incarnato, situato e auto organizzante nel quale le azioni e le disposizioni occupano un ruolo decisivo. Da questo punto di vista, la coscienza non è una prerogativa esclusiva degli esseri umani, ma è diffusa nel mondo naturale grazie ai processi evolutivi. Noi sosteniamo che i sistemi artificiali come i robot attualmente sono carenti del tipo di relazione con la corporeità e con l’ambiente che consente quel tipo di auto-organizzazione indispensabile per l’emergenza della coscienza. (shrink)

I argue that the fundamental dogma that all necessary relations are internal is ungrounded. To motivate my argument, I analyse Moore’s classic ideas on internal relations and take them as an illustration of the common form of reasoning that can mislead us to conclude that all necessary relations are internal. That reasoning illicitly smuggles the idea that necessary properties and relations reflect on identity—in the sense that the loss of a necessary property/relation is a loss of identity—into the separate idea (...) that the loss of a necessary property/relation is a loss of essence. Essence, however, is not identity. So the way seems to be open for the existence of necessary properties/relations which do not belong to the essence of entities; that is, the existence of necessary but external relations. I then offer some examples of such relations. (shrink)

A partir algunas aseveraciones que se encuentran en Los Ensayos y en el Segundo Tratado sobre el Gobierno Civil se puede pensar que para Locke cuestiones básicas sobre la Ley Natural tienen su fundamento en principios teológicos, no obstante, en este escrito se tiene por objetivo mostrar que, aunque el origen de la Ley Natural sea divino, difiere de la forma como se adquieren los contenidos de la mencionada ley y del principio o motor por el cual la voluntad se (...) adhiere a esos contenidos en virtud de lo cual un ateo pueda conocer y estar sujeto a la Ley Natural. (shrink)

There are two inspirations for the theory presented. One is the Kantian idea that a free choice affects a deterministic sequence of events globally rather than just locally. The second is the Leibnizian idea that God chooses for actuality the possible world he deems best. But instead of God choosing, suppose free agents collectively do. Let actuality be an office which deterministic possible worlds are voted in and not of. In this way free choice can change things even if every (...) event is fully governed by deterministic laws: free choice substitutes one deterministic world for another. One way to look at the actual world on this theory is as a patchwork of segments of possible worlds. This gives the theory two advantages over familiar compatibilisms: it explains how the future is unsettled until chosen, and it allows that free choices are spontaneous. (shrink)

Preface/Introduction: The question under discussion is metaphysical and truly elemental. It emerges in two aspects — how did we come to be conscious of our own existence, and, as a deeper corollary, do existence and awareness necessitate each other? I am bold enough to explore these questions and I invite you to come along; I make no claim to have discovered absolute answers. However, I do believe I have created here a compelling interpretation. You’ll have to judge for yourself. -/- (...) What follows is the presentation of three essays I have worked on over the past several years seeing publication for the first time. “Hollows of Experience” was written first as an invited chapter for a collection on the ontology of consciousness. However, when cuts became necessary, my chapter got the knife. Its length has prohibited it from publication in any print journal. “Myth and Mind” was written next as a journal article, but as my involvement with it grew so did its length, so it has also idled on my websty awaiting its call. “From Panexperientialism to Conscious Experience” was written most recently, but it is the only one to have been available to the public elsewhere than my own website. Under the name, “The Continuum of Experience”, it was Target Article #95 on the recently closed Karl Jaspers Forum (for discussion purposes only). -/- I have put them in a different sequence here, for reasons of logical sense. Up first, “Panexperientialism” deals with an idea difficult for many to accept, namely that conscious experience is a particular mode of symbolically reflected experience that is largely unique to our species. However, I aver that experienced sensation in itself (as found, for example, in autonomic sensory response systems) goes “all the way down” into nature, and thus the title, panexperientialism. -/- Understanding this idea is helpful to dealing with the focus on language in Part I of “Hollows”, next, since here speech and general symbolic interaction in general are found to be the catalysts for the creation of our consciously experienced world (our “lived reality”). In Part II, however, I explore how experienced sensations must be coeval with existence, and, with even greater temerity, how all this sensational existence might have arisen within some literally inconceivable background of awareness-in-itself that yet has a dynamism that occasionally breaks into existence as experiential events and entities. (The latter may sound wacky, but physicists and cosmologists are themselves attempting to come to terms with that which seethes with vast potential energy in what they refer to as the quantum vacuum.) -/- “Myth and Mind” was put third since it deals with a major lacuna in “Hollows” — that presumed prehistoric period when members of our species made the painful crossing of the symbolic threshold into the beginnings of cultural consciousness. Speech plays a central role here, too, but I look more at narrative structures from the dawn of self-awareness when ritual and myth became vital to human survival. Why would fantastic stories and bizarre rituals be necessary? I speculate that growing foresight led to the unavoidable realization of certain mortality, from which, in turn, emerged the secondary realization that we were now alive. In contrast to our yet-to-come death, we have life here and now, and by ritually identifying with a symbolically expanded mythic, i.e., sacred, reality, we may continue to live on after bodily death, just as our ancestors and loved ones must also do. Language and mythmaking are necessary to avoid mortal despair and they remain at the core of human consciousness. -/- As Ernst Cassirer (1944) has noted, language and myth are “twin creatures”, both metaphoric webs over a reality we can never wholly comprehend. We live in the symbolic and construct our works of imagination and wars of conquest to make life meaningful, to feel immortal, and to sense that we ourselves participate in a reality greater than ourselves. No doubt we do, but this does not mean our culturally constructed self-identities survive the death of our bodies, and it does not imply that our symbolic concepts can ever indicate the ultimate truth. We simply must symbolize an extended reality that was sacred to our ancestors: “Is it not our way, as illusory as it may be, to force continuance on our world and our life in the face of their inevitable ending? Are we not compelled to extend those imaginary horizons as far as we can despite the terror and the sometime joy their extension incites? Is their closure not a form of death?” (Crapanzano, p. 210) -/- Of course, this leaves me in the uncomfortable position of being forced to admit that this venture of mine must inevitably be another attempt at meaningful mythmaking. But what else could it be? This is certainly not a scientific proof though it is indeed an academically rigorous exploration. (Just try to count the citations!) I hope the reader will judge my thesis on the basis of its coherence, the sense of meaning it evokes, my intellectual responsibility, and, finally, the engagement it inspires. If you have read my expositions and found yourself immersed in the timeless questions I here call forth, I would call these writings successful (even if you violently disagree with my answers). -/- I am very grateful to Huping Hu for granting me this special issue of JCER in which to present my ideas in some detail. He has patiently dealt with my exuberant approach and allowed the many changes I kept coming up with right until the final publication date. I also wish to thank the many potential commentators who politely replied to my invitation, and, even more, I thank those who made time to write actual commentaries. -/- References -/- Cassirer, E. (1944). An Essay on Man: An Introduction to a Philosophy of Human Culture. New Haven/London: Yale UP. -/- Crapanzano, V. (2004). Imaginative Horizons: An Essay in Literary-Philosophical Anthropology. Chicago: U of Chicago Press. -/- Gregory M. Nixon University of Northern British Columbia Prince George, British Columbia, Canada Email: [email protected] Websty: http://members.shaw.ca/doknyx. (shrink)

Though Arthur Danto has long been engaged with issues of embodiment in art and beyond, neither he nor most of his interlocutors have devoted significant attention to the art form in which art and embodiment most vividly intersect, namely dance. This article, first, considers Danto’s brief references to dance in his early magnum opus, The Transfiguration of the Commonplace. Second, it tracks the changes in Danto’s philosophy of art as evidenced in his later After the End of Art and The (...) Abuse of Beauty. And finally, it utilizes Danto’s most recent work on the philosophy of action to suggest a new Danto-inspired definition of art, namely "apposite bodies.". (shrink)

CONVERGENT REALISM AND ITS RIVALS (joining the realism-antirealism debates in modern Western philosophy of science). Rinat M. Nugayev, Kazan branch of Russian University of Cooperation. Abstract. Arguments pro and contra convergent realism are considered. It is argued that to meet the antirealist challenges convergent realism meta-programme hard core should be modified significantly . However well-known rivals of structural realism – entity realism (N. Cartwright and I. Hacking) and structural realism (John Worrall) – are mere revisionist versions of convergent realism based (...) on ad hoc modifications of the solutions first obtained within antirealist programme. (shrink)

Niettegenstaande de tendens van het failliet van het multiculturalisme is multiculturele dialoog niet weg te denken in een zich globaliserende wereld. Taylor, Gadamer, Honneth en Kymlicka hebben een bijdrage geleverd op het vlak van de erkenning van identiteit, respect en waardering van verschil. Wij voeren het argument aan dat bovenstaande auteurs niet ontsnappen aan het postmodernistisch dilemma van zelfautonomie en slachtofferschap. Dit komt doordat zij in hun rationale vertrekken van het afzonderlijke subject en deze situeren in een ruimte-tijd waarin de (...) tijd slechts een historische rol heeft en de ruimte geen actieve rol speelt. Tegenover deze uitvloeisels van het postmodern denken stellen wij het eco-communau-tarisme. Vanuit de vaststelling dat het individu denkt, spreek en handelt in de context van zijn taal en cultuur en dus vanuit zijn gemeenschap, situeren wij dit subject en de gemeenschap tevens in een particulier territorium of het ecotoop. Door middel van Hacking’s sociaal constructivisme, het Leibniziaanse meerwereldenbeeld en het biologische paradigma als nieuw denkkader, structureren wij de gemeenschap volgens een cyclisch en een lineair tijdverloop. Het cyclische waarborgt de traditie van een gemeenschap, het lineaire doet de gemeenschap evolueren naar een moreel betere toekomst en heeft een transcendent statuut. Het eco-communautarisme biedt het kader voor een kwalitatieve evolutie van individuen en gemeenschappen. Het normerend aspect hiervan is de pluriforme en multiculturele dialoog. (shrink)

In this paper, we introduce and investigate a new class of sets and functions between topological space called neutrosophic semi-supra open set and neutrosophic semi-supra open continuous functions respectively.

I have a theory of the emotions that many people find unflattering. I contend that all emotions, as such, are negative and neither life-enhancing nor truth-connected. In this essay, I present this theory and my reasons for it.

A methodological model of origin and settlement of theory-choice situations (previously tried on the theories of Einstein and Lorentz in electrodynamics) is applied to modern Theory of Gravity. The process of origin and growth of empirically-equivalent relativistic theories of gravitation is theoretically reproduced. It is argued that all of them are proposed within the two rival research programmes – (1) metric (A. Einstein et al.) and (2) nonmetric (H. Poincare et al.). Each programme aims at elimination of the cross-contradiction between (...) the special theory of relativity and Newton’s theory of gravitation. New arguments in favor of Einstein’s programme are given. Nevertheless, this does not imply the necessity to rule out all the nonmetric theories, since Einstein’s and Poincare’s programmes are alternative only as different tools of the cross-contradiction elimination. In the other respects these programmes are complementary: description, explanation and prediction of gravitational experimental data entails the usage of the languages of nonmetric theories as well as of metric ones. The part of the present investigation elucidating the necessity of nonmetric theories is an implementation of the ideas of A.Z. Petrov, the founder of Kazan University Relativity Department. Late Alexei Zinovievich had frequently punctuated that the notion of Riemann space-time continuum common for all metric theories obfuscates all the gravitational notions considerably and hampers the analogies with other physical theories at hand. Since the ambiguity is a hallmark of all the general relativism notions, approach to their definitions “should be determined not by analogies and contingent facts, but by general considerations linked the physical measurements theory… No matter how far the events lie out of the frames of classical physical explanations, all the experimental data should be described by classical notions” (Petrov, 1965,pp. 59,66). Key words: Kip S. Thorne, A.P. Lightman, Stepin, theory of gravity . (shrink)

An apparent incommensurability of two leading gravitational paradigms (metric and nonmetric) is considered. It is conjectured that the application of neutral language of A.P. Lightman, D.L. Lee and Kip S. Thorne (“The Foundation of Theory of Gravitational Theories”. Phys. Rev. D 1973, vol.7, pp.3563-3572) can help to solve the theory –choice problem in principle. Key words: neutral language, theory choice, gravity.

The history of sciences in Moslim countries is contemplated. The reasons of initial flourishing and subsequent decline of Moslim science are discussed. It is conjectured that one of them may consist in the lack of analogue of protestant revolution the Moslim World.